1. Field of the Invention
The present invention relates to an apparatus for securing and locking interfaces of two items releasably together and more particularly to an apparatus for securing and locking together an array of electrical connectors in a common frame.
2. Brief Description of the Related Art
A variety of mass interconnect devices have been used in the past. One example of prior art interface systems was disclosed in U.S. Pat. No. 4,329,005, entitled “Slide Cam Mechanism for Positioning Test Adapter in Operative Relationship with a Receiver,” which was assigned to Virginia Panel Corporation. In the '005 patent, the receiver included an inner frame and outer walls. Between the outer walls and adjacent sides of the receiver frame were placed fixed hanger plates provided with straight slots and interior slides having coacting cam slots. The slides were driven by a hand lever and attached round torsion shaft with connected linkage having an over-dead-center locked position. Movement of the hand lever would cause the slides to move parallel to the outer walls and interior sides. Modules for holding various electrical contacts were mounted in the receiver parallel to the direction of movement of the slides.
The individual test adapter, or ITA, had four split roller dual bearings or rollers on common dry lube sleeves that would rotate oppositely during the camming action to minimize friction. The individual test adapter rollers rested on dwell shoulders of the cam slots and then descended through the straight slots during movement of the slides of the receiver to produce positive straight-on engagement of the test adapter and receiver multiple contacts. The slides had elongated linear guide bearings with dry lube pads for precision free movement. The slides were connected to a cylindrical torsion shaft via linkage. Like the receiver modules, the ITA modules were mounted in the system in a direction parallel to the ITA sides on which the rollers were located. When modules, pins, patchcords, and perhaps a cover are mounted to or on the interface test adapter, the assembly is sometimes referred to as a “fixture.”
Another prior art system has been known as the MAC Panel Series 06, or rotating latch, interface device. In the rotating latch type device, the camming is performed by plates that rotate rather than moving in a linear fashion. In the rotating latch devices, the connector modules have been mounted to the receiver and test adapter frame parallel to the plant of rotation of the rotating latches.
Another prior art system sold by Virginia Panel Corporation included a receiver that included slides similar to those disclosed in the '005 patent but used pins at two corners, diagonal from one other, on the receiver. These pins inhibited vertical movement of the ITA in the receiver to produce straight-on engagement. This prior art system included machined side rails and a cylindrical torsion shaft.
Another prior interface device is known as the TTI Testron VG Series interface device. This device may be in a tabletop or a rack-mounted form. This VG Series device included a fixture support plate mounted to the receiver in a direction perpendicular to the face of the receiver. The receiver would be mounted directly to the test equipment.
The TTI Testron fixture, or test adapter, would be engaged to the receiver by lifting the fixture onto a pair of hooks protruding from the face of the receiver and then resting the fixture on the support plate. A handle and gears were used to pull the hooks, and hence, the fixture, into the receiver to cause the electrical contacts in the receiver and the fixture to mate.
Yet another prior art test system was used prior to 1980 in connection with the federal government's F-16 program. That system had a slide plate on each side of the receiver, with each slide plate connecting to the engagement pins on the sides of a corresponding ITA frame and each slide plate being pulled into the receiver via a connection near the center of the slide plate. This system suffered from significant problems of the ITA tilting to some degree and thereby causing contacts to be crushed.
Still other prior art engagement systems include those disclosed in U.S. Pat. No. 5,966,023. In still other prior art engagement systems, others have incorporated the use of a screw together engager that utilizes a range of thread styles including standard, Acme and high pitch helical grooves. The amount of rotation to engage these ranges from 180° to several full turns. One example of such a screw type engager is disclosed in U.S. Pat. No. 5,562,458 entitled “Interface Engagement and Locking System.”
The systems that utilize standard threads or single start Acme threads typically require several turns to fully engage. Although they do not need lubrication, they have a tendency to cross-thread easily. The systems that employ helical grooves typically only require 180° of rotation to achieve full engagement but require a high amount of torque and the use of lubrication to maintain an only somewhat smooth feel during the process of engaging and disengaging. Even with the use of lubrication, these systems show a consistent pattern of extremely high wear on some of the components involved in the engagement procedure. The torque and the wear issues worsen over the cycle life of the system. Also, considering the geometry of these systems, the lubrication is required to be applied in an area that threatens sensitive electronic components.
Another more recent system is disclosed in U.S. Pat. No. 7,297,014, which is hereby incorporated by reference. That system incorporated a spring lock design to initially attach the two halves of the system, i.e., a receiver and a test adapter, together after which the use of a multi start Acme lead screw provided a, consistent, low torque means of engagement. The test adapter had a single spring lock pin extending roughly down the center of the test adapter toward the receiver. The single spring lock pin had a plurality of tab near its tip. When engaging the test adapter with the receiver, the tabs on the spring lock pin were initially engaged with a groove or ridge in an opening in the receiver adjacent the spring lock pin when the test adapter is aligned with the receiver for engagement. Thereafter, the handle on the test adapter was turned to cause the Acme lead screw to provide a constant low torque means to draw the test adapter into the receiver via the groove or ridge, which may be referred to as a spring lock bushing in the opening in the receiver.